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v W. F. BROWN.

CUT-OFF VALVE GEAR.

f No. 402,557.' Pate ed May 7, 1889.

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W. P. BROWN.l

GUT-UFF VALVE GEAR. No. 402,557. 4Patented May '7, 1889.

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W.v F. BROWN.y

. i GUT-OPP `VALVBGEARI f No. 492,557. l atented May '7, I1889'.

Y, Flan/n INVEN-ma.

UNITED STATES :PATENT OFFICE.

WALTER F. BROWN, OFFROVIDENOE, RHODE ISLAND.

CUT-OFF-VALVE' GEAR.

sPEcIFIcA'rIoN forming part of Letters Patent No. 402,557, dated May 7, 1889.

Application nea october 29,' 18sa serrano. 289,366. (rommel.)

To @ZZ whom t may concern.-

Be it known that I, WALTER F. BROWN, a citizen of the United States, residing at Providence, in the county of Providence and State of Rhode Island, have invented certain new and useful Improvements in Cut-Off-Valve Gears; and I do hereby declare the following to be a full, clear, and exact description of the Invention, such as will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings, and to letters Ortigures of reference marked thereon, which form a part of this speciiicatiom My invention relates to the valve-gear of automatic cut-off engines of the four-valve or Corliss type; and it consists, essentially, of a loosely mounted double acting or camgrooved disk connected with the governor, in combination with the main operating-arm or hook-lever provided with a tripping-lever engaging said, cam, and a valve-arm or steamlever secured to the valve-stem and arranged to engage the tripping-lever, all as will be more fully hereinafter set forth and claimed.

Heretofore, or at least usually in engines of the class .referred to, the construction has been such that the act of cutting off or releasing the steam-valve imposes considerable extra work upon vthe governor for the time being, by reason of the thrust or resistance due to the engagement of the tripping-lever with the governor-connected knock-off. A natural result of such construction is that the govern or is continually Iiuctuating independently of thev changes or variations in the work or load upon the engine. Another Vobj ection to such former construction is that itnecessitates the employment of a spring for returning the tripping-lever to its normal position after it has released the valve. The use of a spring for this purpose is especially Obj ectionable, because it increases the work upon the SCI governor by an amount equal to the resistance of the spring in returning the trippinglever, as stated. The use of such springs also produces considerable noise in working.

Y The obj ect I have in view is to provide an engine with a positive hooking-on device in which sprin gs are entirely dispensed with. It also combines an arrangement for positively closing the steam-valves, the construction being Ysuch that the work upon the governor in cutting off is greatly reduced, thereby rendering it more sensitive. In designing my 1m- -proverments I have also studied to reduce the cost of manufacture.

Another advantage of my improvement is that the fulcrum of the hook and tripping-lever is located somewhat below the line of pressure of the contact-surfaces of the hook-plates, thereby nearly balancing or neutralizing the resistance required to trip the valve. A slight preponderance in leverage, however, is given to the hook, by means of which the latter is inclined to engage the hook plate of the steam-lever rather than to disengage it. By reason of this arrangement the work imposed upon the governor in releasing or tripping the valve is actually reduced to a minimum;

In the accompanying three sheets of drawings, Figure Sheet 1, is a side elevation of a portion of a cut-off-valve gear embodying my improvements, the parts being in the normal or hooked-On position. Fig. 2 is an end view, the several rods or connections be ing broken OIT. Fig. 3 is an end View, in reduced scale, of the cam-grooved double-acting cam detached. Fig. et is a similarly-reduced view of the hook-lever adapted to be actuated by the Wrist-plate. Fig. 5, Sheet 2, is an end view substantially as shown in Fig. 2, the relation of the parts corresponding to the unhooked or tripped posi-tion. Fig. 6 is a perspective view of a rectangular steel block adapted to be attached to the steam-lever. Fig. 7 is a similar view of a bolt having a square steel -headed platey adapted to be mountedin the hook or latch to engage said steel block. Fig. 8 is a sectional view taken through the head of the bolt. Fig. 9 is a side elevation of a Corliss cylinder, showing the manner of mounting and connecting my improved valve-releasing gear. Fig. lO, Sheet 3, is a side elevation showing my improvement reversed in the manner of its application. Fig. ll`is an end view of the same, the

parts being hooked on and in the actof moving to uncover the steam-port; and Fig. 12 is a side view, detached, of the bolt-carrying arm of the hook and the steel block of the steamlever, showing more clearly that the line of contact of the surfaces of the hook-plates is above the' center or fulcrum of the arm.

IOO

A more specific description of my present invention is as follows: I would iirst state, however, that my improvements are more particularly adapted to be applied to a fourvalve engine. Acylinder of this class is indicated by C2, Fig. i), the general arrangement and manner of actuating the valves being substantially the same as characteristic of the well-known Corliss engine. A wrist-plate, W, is pivoted to the center of the cylinder, the same having a pin, E', adapted to be jointed to a rod taking its motion from the eccentric, as usual.

E, Fig. l, designates the back cover or bonnet for the steam-valve, and s indicates the valve-stein mounted to vibrate in said bonnet. The outer portion of the bonnet is turned off to form a bearing for the looselymounted hook-lever A and the do uble-acting governor-connected disk C. To the outer or free end of the valve-stem is keyed the steamarm or bell-crank lever B. One arm, b', of this lever hasl its outer end provided with a pin, b2, to which is jointed the drop-rod CZ. The purpose of the drop-rod is as commonthat is, it serves, in combination with a weighted piston mounted in a vacuum-chamber in falling, to quickly close the steam-valve immediately succeeding the tripping of the steamarm by the action of the governor, &c. The other arm, b, (which is nearly vertical,) of the lever B is planed across at its lower end, b3, to form an elongated seat or abutment, b2, against which a face of the rectangular steel block n is adapted to bear. The arm b is drilled parallel with the seat b2, to receive a headed bolt or screw, o, having the said block n secured to its lower end, the bolt being so fitted that it may move freely up and down in the arm b. The outer or front face of the block n is adapted to engage a vertical face of the steel plate r, mounted in the hook f. By means of this construction and arrangement the line of pressure of the arm B and hook f in working is substantially in the same plane and well within the bearing of the looselymounted main or hook lever.

The lever A, as before stated, is mounted to freely vibrate on the hub of the back bonnet. The upper portion or arm, a, of said lever has a pin, c', mounted therein, to which is jointed a link or connection, Z, also jointed to and receiving motion from the wrist-plate W. The

A lower portion, a', of the lever A is provided with an elongated hub, c, at its free end, the same being drilled to receive a shortl shaft, m, to which the two parts f t, constituting the releasing-lever, are secured. The hook portion f, which lies nearly horizontal in its normal position, is provided at its free end with a square-headed steel bolt, p'.

In Figs. 7 and 8 the head r is represented as a square plate, through which said bolt passes. This construction readily permits of the substitution of a new plate when necessary. A portion of the hook f is enlarged, as at j", contiguous to the hub, thereby, in connection with a similarly-arranged surface formed on the back of the block-carrying portion of the steam-arm, serving, when the two surfaces are in engagement, to positively close the valve; or, in other words, in case the droprod fails from any cause to drop the proper distance, the action of the lever A, as it approaches the end of its stroke, forces the surface f against the steam-arm, and thus insures the complete closing of the valve. The tripping-lever t is secured to the rear end of the shaft m, the same having its free end provided with a truck-roll, t2, arranged to travel in a cam-shaped slot, e. By means of this arrangement it will be seen that the axial movement of the shaft m is coincident with that of the roll t2 in its passage along the slot e.

C indicates the cam-disk, the same being loosely mounted on the hub of the bonnet E and at the rear of the lever A. The disk is provided with a double-acting cam-groove, e, the latter being so arranged with reference to the center or axis of the disk as to produce three concentric sections'united by the actual cam-surfacesz' i. (See Fig. 3, dac.) The camdisk is connected with the usual governor mechanism by a link or rod, g, jointed to the disk, whereby the cam is axially vibrated as required, to effect the proper point for releasing'the valve. We will assume now that an engine is provided with my improvements, and that it is arranged to revolve in a forward direction, "the position of the several parts constituting the valve-gear being substantially as represented in Fig.A 9, wherein the back steam-valve is in-the act of being opened to uncover the port to force the piston ahead on its forward stroke, (the front steam-port meanwhile being covered by the tripped valve,) the corresponding position of the steam-arm, &c., being represent-ed in Fig. 2.

It will be seen by referring to the drawings that the cam-roll t2 is in that portion of the groove e nearest the axis of the valve-stem, (or intermediate of the end portions,) thereby acting to maintain the hook f in engagement with the steel block n. The continued movement of the wrist-plate forces the steam-arm B in the arrow direction, thereby uncovering the steam-port, and at the same time lifting the drop-rod d and its connections,-the roll t2 meanwhile traveling in the center section of the concentric portion of the cam-groove e until it meets the cam -surface i when the latter causes the tripping-lever to outwardly vibrate upon its axis a distance equal to the cams offset, thereby unhooking the trippinglever and releasing the valve, after which the drop-rod, dto., acts to close the steam-port, thus effecting the cut-olf.

In case the load upon the engine is reduced the governor will immediately act (for the time being) to vibrate the disk C in a direction contrary to the movement of the connected levers A and B. The conjoint movement of the said parts causes the cam-roll to IOO IIO

pass down the cam-surface 0." earlier, thereby releasing the valve, vas just described, the relative position of the Aseveral parts being substantiallyfas represented in Fig. 5.' During the remainderof the stroke of the wristplate `the roll t2 will travel idly in the concentric portion of the slot e. Upon the returnstroke of the wrist-plate W the roll will reverse its movement, (the lever B meanwhile remaining stationary.) When the roll reaches and passes upon the said cam-surface t', the steel plate r will come incontact with and pass under the tripping-block n, the latter, with its bolt o, freely rising and instantly dropping again to its normal position by gravity-as soon as the plate p has passed. As the hook-lever A approaches the end of its rearward stroke, the lug f of the hook f will engage the rear side of the steam-arm (if the port is not already fully lapped by the valve) vand force the lever Bv to travel to its limit.

The valve remaining thusu closed until the next forward stroke of the wrist-plate causes` the tripping-lever, &c., to again act to open the valve, as before described.

In case thel governor-belt breaks or the governor becomes inoperative through any cause While the engine is running, the connections g will act to carry the disk C in the eXtremeopposite direction, (see arrow ft, Fig. 2,) thereby causingk the roll t2 to pass down the camsurface t' of the cam-groove, by means of which movement the hook'is prevented-from engaging the latch-block n and-positively precluding the parts from hooking on to open the steam-valve. f

It will be seen, Fig. l2, ttc., that the axis ot' the tripping-lever and hook is so arranged with reference to the line of pressure of the hook-plates that the resistance required to trip the valve is nearly balanced.'` The hook f, however, is given a slight increase in leven' age, .thereby producing a tendency of the hook-plates to engage each other instead of disengagement. Bymeans of this arrangement of the levers and hook-plates the work of releasing or tripping the valve by the governor is reduced to a minimum.

I would state as another advantage resulting from the employment of my improvement thatin the event of serious wear upon'the' the parts is, however, practically the same as The action of rily, although the latter form is more symmetrical:

Iclaim as myinvention` 1. The governor actuated double acting cam-grooved disk and the pivotally-mounted hook and tripping-lever connected with said cam, anda steam-arm having a latch-block adapted to engage said hook, substantially as hereinbefore described, and'for the purpose set forth.

2. In a cut-o valve, the combination, with the governor actuated doubleacting camgrooved disk, of a pivotally-mounted tripping-lever and hook taking its axial movement from said cam, substantially as shown and h'ereinbefore described.

3. In a cut-off-valve gear, thecombination, with the steam-arm and hook-lever, of a loosely-mounted tripping-lever and hook traveling in unison with said hook-lever, and a loosely-mounted double-acting cam-grooved disk actuated by the governor and having an arm of the said tripping-lever connected with stantially as hereinbefore described, and for the purpose specified.

et. In 'a releasing or cutoff-valve gear, the combination, with a steam-arm having a drop- 'rod' and a loosely-mounted latch-block, as n, carried by said arm, of a pivotally-mounted hook arranged to engage said latch-block, a

tripping-lever and hook and oscillated by the ing the tripping-leverengaging said cam, whereby'the-mov'ements of the lever A and cam, individually' or conjointly, act to oscilinbefore described, and for the purpose specified.v

5. In a cutoff-valve gear, the combination, with the loosely-mounted governor-actuated double-acting cam-grooved disk hereinbefore described, of a suitably-mounted hook, asf, axially vibrated by means of said cam and arranged to engage the steam-arm,&c., of the valve-gear, substantially as set forth, and for the purpose stated.

6. In a cut-oft-valve gear, the combination, with the loosely-mounted governor-actuated camgrooved disk, as C, of the pivotallying the tripping-lever, a fixed steam-arm, B, provided with a drop-rod and latch-block, as n, -mounted to move up and down in the arm,

son with the said tripping-lever and provided with a lug, as f, to engage the steam-arm to positively close the steam-valve, the whole combined, arranged, and operating substantially as shown'and described.

and workedV by said groove of the cam,"sub V engine, and ajpositive-acting or cam-grooved disk, as C, actuated by the governor and havlate the tripping-lever, substantially as heremounted tripping-lever t, vibrated by saidV can1,`a loosely-mounted hook-lever, A, carryand a hook, f, secured to and moving in uni-V lworking or hookl lever, as A, carrying the IOO IIO

7. In a cutoff-valve gear, the arrangement of the axis of the tripping-lever and hook-below the line of pressure of the contact-surface of the hook-plates, substantially as shown,

whereby the resistance or work required to being` Connected to the Cam-groove, Substmi- 1o trip the valve is nearly balanced, thereby also tially as shown and set forth. relieving the governor and rendering' it more In testimony whereof I have alixed my sig sensitive in Working, Substantially als hereinnature in presence of two Witnesses. before described. I T 7 T 8. In a cut-oi-valve gear, the Combination i V ALTER F' BRO" b' l NVitneSses: f CHARLES HANNIGAN,

GEo. H. REMINGTON.

of ay governor-actuated eain-grooved disk, C, and a pivotally-mounted tripping-lever and hook positively vibrated in each direction by 

